Crop gathering augers known in the art can be equipped with one or more components to assist with feeding crop material from the grain header into other parts of the harvester. For example, some augers include hard fingers made of steel or other rigid material that protrude radially outwardly from a central region of a drum. The fingers rake crops into an inlet opening of a feeder, which in turn conveys the crops into a threshing system of the combine. U.S. Pat. No. 6,640,527 to Farley et al., the content of which is incorporated by reference herein in its entirety, illustrates one example where auger fingers are used. As illustrated in Farley et al., the auger fingers are typically mounted on an auger finger shaft or other element located within the auger drum in an axially offset relation to a rotational axis of the drum, and protrude radially outwardly through holes in an outer cylindrical surface of the drum.
Referring to FIG. 1, a conventional rotating auger 34 is shown which uses auger fingers to convey crop material from a grain header 24. The rotation of auger 34 is denoted by arrow B, about axis 42 through a drum 36. Drum 36 is hollow, and it includes a longitudinally and angularly spaced array of holes 46 through an outer cylindrical surface 44. For purposes of illustration, four auger fingers are shown, namely auger fingers 48, 48A, 48B and 48C. Auger fingers 48, 48A, 48B and 48C are positioned in and extend outwardly through the holes 46. Each of the auger fingers 48, 48A, 48B and 48C telescopically extends outwardly through its associated hole 46 by a different amount, depending on the rotational position of drum 36 about axis 42. For example, auger finger 48 is shown in a first rotational position telescopically extending in an upwardly and forwardly directed orientation from drum 36, in preparation for raking. Auger finger 48A is shown in a second rotational position of drum 36, telescopically extending forwardly and downwardly in a raking position and orientation. Auger finger 48B is shown at a third rotational position of the drum, extending rearwardly and downwardly and mostly telescopically retracted into, the drum. Finally, auger 48C is shown in a rearward and upwardly directed orientation re-emerging from drum 36.
By rotation of drum 36 in the direction denoted by arrow B, auger fingers will project telescopically a substantial distance from drum 36 in a gathering or raking mode through a portion of a revolution of the drum, as seen with fingers 48 and 48A, and then will retract into drum 36 through another portion of the revolution, as seen with augers 48B and 48C, once the crop has been raked rearwardly into the feeder. Generally speaking, the auger fingers will latch onto and rake crop material as the fingers project more and more outwardly from the drum, and release crop material as the fingers are retracted more and more into the drum. As each auger finger rotates about the auger finger shaft, the auger finger reciprocates between a fully projected position, at which time the finger projects a maximum distance through the drum, and a fully retracted position, at which time the finger projects a minimum distance through the drum. Each auger finger reaches the fully projected position at some point while rotating around the front-facing side of the auger, and reaches the fully retracted position at some point while rotating around the rear-facing side of the auger.
One drawback of conventional auger finger assemblies is the failure of auger fingers to reach the fully retracted position at the appropriate point during a revolution. Some auger fingers reach the fully retracted position at a point too far past the location where the crop material must be released in order to be fed to the threshing system. In the auger shown in FIG. 2, for example, the fully retracted position Pmin is located on the rear-facing side of the drum, offset from the fully projected position Pmax by an angle of 180 degrees. It takes one-half revolution around the drum for each finger to move from its fully projected position Pmax to its fully retracted position Pmin. Therefore, the auger fingers do not reach their fully retracted position Pmin until after they pass the inlet to the threshing system and continue their upward rotation toward the front-facing side of the drum. In this arrangement, crop material that clings to the ends of the auger fingers can be pulled past the inlet of the threshing system and carried back over the drum. Material that is carried back over to the front-facing side of the drum combines with new crop material entering the header. This can cause an accumulation of crop material that can plug up the auger and/or inlet to the feeder.